VBA looping in excel

I would like to create a for loop using string value for increment from the code below you will see that I have created an x = string and I want to change as a string to find multiple text into my sheet and then copy and paste into another sheet in specific cell location

Sub looping()

'Finalrow = Cells(Rows.Count, 1).End(xlUp).Row

x = "PS - Wtotl"
y = "DO-SSPop"

For s = x To Len(x)
Windows("usco2010.xlsx").Activate
Selection.Find(What:=x, After:=ActiveCell, LookIn:=xlFormulas, _
        LookAt:=xlPart, SearchOrder:=xlByRows, SearchDirection:=xlNext, _
        MatchCase:=False, SearchFormat:=False).Activate
Cells.FindNext(After:=ActiveCell).Activate
Range(Selection, Selection.End(xlDown)).Select
    Selection.Copy
Windows("usco2010.xlsx").Activate
    Sheets.Add After:=ActiveSheet
    ActiveSheet.Paste
Next s

End Sub